2005 Vauxhall Corsa ECU

I was an RAC tech for years and only ever saw this fault on a couple of occasions? No guarentees can be made this will not happen again but I would feel happy that it happened under warrenty not later in it's life? This fault will not affect any other part of the car once it has been repaired

The way I read your first post, I thought your ECU had broken and was being replaced. If you are getting fault codes appearing this is a differnent matter. The ECU is designed to tell you when there is a fault and therefore the MIL light will flash from time to time when there is a fault. If your mechanic has cleaned the lambda sensor. And it shows the same fault when you take it back to him. Then he should replace the lambda sensor. Some sensors are a little sensitve and will flash a code for the least little thing. Ask your mechanic to check all corresponding parts. Could you please ask your mechanic what the fault code number is and repost to me. If one of your cylinders is not firing ie. Coil not genertating a spark. Then fuel is not getting burnt in that cylinder and throwing it out of the exhaust. This will pick up on the lambda sensor hence the fault code. When the actual fault lies in one of the coils? A coil misfire should generate a seperate code but this is not always the case.